In the field of mobile data communications, it is known for mobile terminals to roam from a first network in a first country to a second network in a second country. It is also known, in some circumstances, for users to roam between networks in a same country. When roaming, it is not uncommon for subscribers using the mobile terminals to require mobile data services. Such mobile data services are known to be provided by Global System for Mobile communications (GSM) networks supporting a General Packet Radio Service (GPRS), and third generation (3G) Universal Mobile Telecommunications Systems (UMTS) networks.
As part of the infrastructure supporting both the GPRS service of the GSM networks and the UMTS networks, Serving GPRS Support Nodes (SGSNs) are provided to support mobility and data session management. Additionally, Gateway GPRS Support Nodes (GGSNs) are provided to serve as a gateway between the GSM networks and/or the UMTS networks and an external packet data network, such as the Internet. From a network management perspective, it is desirable to monitor traffic flowing between a given SGSN in a “visited” network in which the mobile terminal is roaming and a given GGSN of a “home” network. Conversely, it is also desirable to monitor traffic flowing between an SGSN of the home network being accessed by a mobile terminal roaming in the home network and a GGSN of another network from which the mobile terminal originates, the another network constituting a home network from the perspective of the mobile terminal. Network management and reporting systems concerned with subscriber roaming must be able to determine both an origin and a final destination of network traffic in order to identify the network from which the traffic originates and the network in which the traffic terminates. This information allows the network in which the mobile terminal is roaming to be identified and also the home network of the mobile terminal to be identified.
GPRS-enabled mobile data networks and UMTS mobile data networks use Internet Protocol (IP) network addresses to route traffic directly from the visited network in which the mobile terminal is roaming to the home network of the mobile terminal.
However, in order for a network management application, for example a billing verification application as used in conjunction with an AcceSS7 network monitoring system produced by Agilent Technologies, Inc., to make use of associations between IP addresses and networks, it is necessary to perform a look-up operation. Therefore, reference is made to a so-called address network name table of MCCs, MNCs and IP addresses, each entry of the table comprising an MCC/MNC/IP address tuple.
Currently, construction of the table is a manual process of providing a spreadsheet of IP Addresses, MCCs, and MNCs, typically carried out by a GPRS Roaming Exchange (GRX) supplier, since the GRX supplier has knowledge of IP addresses being used in different networks. To compile the table, a so-called “protocol analysis session” is run by an administrator of a Roaming Management System (RMS) of the acceSS7 monitoring system on Gp links of the home network to verify IP addresses in the table. Obviously, errors need to be identified, and so a troubleshooting stage needs to take place, but this requires expenditure of time by engineers. Clearly, manual compilation of the table is therefore prone to human error, and even if substantially error free, IP addresses listed in the table can become disused or re-allocated. Hence, compilation of the table is an extremely laborious and time-consuming activity.
Furthermore, as GPRS networks expand and evolve to become UMTS networks, network operators are constantly allocating and reallocating IP addresses to switches. In the case of GPRS and UMTS networks, the GGSNs can have up to 32 active IP addresses each and these are subject to periodic change, for example as a result of network engineering activity, further exacerbating the problem of maintaining accuracy of the table. Additionally, a given network operator can have a number of GGSNs having IP addresses that may be contiguous, but alternatively may be on different subnets. Further, the IP addresses of the GGSNs may be paired-off as dual redundant nodes. Therefore, disparate and unrelated IP addresses may be associated with different GGSNs, resulting in an absence of consistent patterns of IP addresses that could be used by the GRX supplier to simplify the manual process of compiling the address network name table.
Without accurate maintenance of the table, management reporting systems and roaming management systems will not operate correctly, resulting in the generation of false alarms, investigation of which wastes time.